The purpose of this investigation is to study the metabolism of epiphyseal cartilage in normal and dwarfed children. At the present time very little is known about the growth processes occurring at the physis and what causes the decreased growth seen in dwarfism. Laboratory animals will be used to identify general requirements of cartilage metabolism; however, the specific abnormalities causing human dwarfism must be studied in biopsy material from the dwarf himself. In order to make these studies without injury to the child, organ culture of iliac biopsies will be made. By this technique dwarf cartilage can be compared directly to the normal. I anticipate that this investigation will give information of the causes of dwarfism and add to our knowledge of normal human cartilage metabolism.